Have scientists found a way to read your mind?

Many who saw the movie "Minority Report" experienced two distinct reactions: first, "Please, this is pure science fiction" and then, "There but for the grace of God..." Really, how many of us have not fantasized at least once about what we would do if we ever came upon that guy who stole our car? And maybe on a trip to Best Buy, you imagined for a second what it would be like to just pick up that 60-inch DLP out-of-the-box set, hoist it on your back and walk out of the store. Would you get tackled by a salesperson?

But these are just passing thoughts, even the stuff of jokes. They're not actually plans, right? The distinction between the two is just a part of the ethical debate surrounding a study published in the journal Current Biology in February 2007, which reports the findings of an experiment on reading people's intentions. The study, led by John-Dylan Haynes of the Max Planck Institute for Human Cognitive Brain Sciences in Germany, shows that through brain scans and corresponding computer software designed to correlate specific brain activity with specific thoughts, researchers are able to read people's intentions with great accuracy.


How did they do it? Find out on the next page.

Reading Minds and Intentions

The scientists who performed the study used functional MRI (fMRI) to monitor subjects' brain activity while they formed and held an intention. The researchers told each subject that they were about to see a set of two numbers, and they should decide beforehand what they wanted to do with those numbers -- either add them or subtract them. There was a several-second delay during which the subjects were supposed to focus on this intention. By clearly separating the intentions from the numbers themselves and the subsequent mathematical action, the researchers sought to isolate the brain activity association with the intended action ("I'm going to add it" or "I'm going to subtract it") from any brain stimulation resulting from the numbers and the calculations.

The brain scans were one part of the study; the other part went on behind the scenes. The researchers had to decide which types of brain activity would indicate which intention in order to establish a computer algorithm that would read the fMRI results. The software incorporates a high degree of complexity. Brain patterns are not necessarily localized; sometimes, in order to fully grasp what's happening, you need to be able to interpret patterns from different parts of the brain simultaneously. Technological innovation plays a large part in what appears to be a successful attempt to read people's minds.


Using a combination of the brain scans and the computer software, researchers were able to "guess" whether the subject intended to add or subtract the upcoming numbers with 70 percent accuracy -- not a bad success rate for mind reading. Activity patterns in the middle of the prefrontal cortex were different depending on whether the subject intended to add or intended to subtract. The researchers essentially looked around the brain and decided, based on all of the activity they were seeing and especially the patterns of stimulation in the prefrontal cortex, whether the brain was preparing to add or subtract.

The study also proved some fascinating hypotheses set forth in other experiments that will no doubt lead to some very speedy progress in the area of mind reading via brain scan:

  • Freely chosen intentions are stored in the prefrontal cortex.
  • Intentions based on external orders are stored in a different part of the brain than those based on internal choice. Intentions based on "following orders" live on the surface of the brain, not deep in the gray matter.
  • When intentions are acted upon, the neural activity moves to a slightly different part of the brain, meaning the brain essentially "copies" the intention and transfers it in order to convert it into action.

The next step in the research is to build on these results to create a sort of mind-reading database of intentions. If scientists can accurately pinpoint the brain activity signaling particular intentions -- such as violent or criminal intentions, the intention to lie, or the intention to read or speak a specific word or move a limb in a certain way, the uses of this process are endless. This is where the ethical debate comes in.

Advances in mind reading can lead to better brain-activated wheelchairs, computers and prosthetic limbs. A person without the use of his hands could think, "I plan to go to check my e-mail," and a computer could open up that person's inbox. But on the darker side, while the current state of the art is very rudimentary, mind-reading technology could ultimately be used to stop a crime before it's even committed, with the government implanting everyone with chips that alert the authorities if a person's brain stores the intention to break the law. But what if that intention is just a passing thought? Some scientists fear this new technology will be put to use before all the kinks are ironed out, and many have called on the scientific community to hold an international discussion on the ethical implications of mind reading.

For more information on mind reading and related topics, check out the links on the next page.